Table 2.
Clinical characteristics of the French-Canadian family study
| |
Probandsa |
Family members |
|---|---|---|
| n = 253 | n = 1031 | |
| Male: Female ratio |
1 : 1.1 |
1 : 1.2 |
| Mean age, yr (range) |
18 (3–50) |
44 (2–93) |
| Smoking status, n (%) |
|
|
| Never |
211 (85) |
473 (47) |
| Ex-smoker |
12 (5) |
342 (34) |
| Smoker |
25 (10) |
197 (19) |
| FEV1, % predicted (SD) b |
92.7 (15.7) |
94.6 (20.3) |
| PC20, mg/ml (SD) c |
2.53 (3.51) |
10.06 (4.97) |
| Serum IgE in μg/l (SD) d |
254.2 (4.9) |
112.4 (4.4) |
| Number of persons with subphenotypes (%) |
|
|
| Asthma e |
253 (100) |
378 (37) |
| Atopy f |
200 (79) |
509 (49) |
| Atopic asthma (Asthma + Atopy) | 200 (79) | 257 (25) |
a Probands are first affected family member recruited in the familial collection and family members refers to other family members who joined the study.
b FEV1 = Mean calculated for the forced expiratory volume in one second evaluated for 217 probands and 770 family members.
c PC20 = Provocative concentration of methacholine that induces a 20% fall in FEV1. Geometric mean and SD evaluated for 192 probands and 711 family members.
d IgE = Immunoglobulin E serum concentration. Geometric mean and SD evaluated for 237 probands and 820 family members.
e Present asthma or past documented clinical history of asthma. The reported mean age of onset is 7 years among the probands and 22 years among the asthmatic family members. Asthma phenotype was evaluated for 1022 subjects.
f Defined as at least one positive response on skin prick test (wheal diameter > 3 mm at 10 minutes). Atopy phenotype was evaluated for 997 subjects.